haskell - http-conduit バージョン 2.0.0.4 のサンプルコードを実行したときのエラーを修正するにはどうすればよいですか?

Question

Haskell は初めてで、http-conduit バージョン 2.0.0.4 のサンプル コードを試していますが、動作しません。

サンプルコードはこちら

{-# LANGUAGE OverloadedStrings #-}
import Network.HTTP.Conduit
import Network
import Data.Time.Clock
import Data.Time.Calendar
import qualified Control.Exception as E

past :: UTCTime
past = UTCTime (ModifiedJulianDay 56200) (secondsToDiffTime 0)

future :: UTCTime
future = UTCTime (ModifiedJulianDay 562000) (secondsToDiffTime 0)

cookie :: Cookie
cookie = Cookie { cookie_name = "password_hash"
               , cookie_value = "abf472c35f8297fbcabf2911230001234fd2"
               , cookie_expiry_time = future
               , cookie_domain = "example.com"
               , cookie_path = "/"
               , cookie_creation_time = past
               , cookie_last_access_time = past
               , cookie_persistent = False
               , cookie_host_only = False
               , cookie_secure_only = False
               , cookie_http_only = False
               }

main = withSocketsDo $ do
    request' <- parseUrl "http://example.com/secret-page"
    let request = request' { cookieJar = Just $ createCookieJar [cookie] }
    E.catch (withManager $ httpLbs request)
            (\(StatusCodeException statusCode _ _) ->
              if statusCode==403 then putStrLn "login failed" else return ())

参照: http://hackage.haskell.org/package/http-conduit-2.0.0.4/docs/Network-HTTP-Conduit.html

ロード時のエラーメッセージ

samplecode.hs:33:39:
    Couldn't match type `()'
                  with `Response Data.ByteString.Lazy.Internal.ByteString'
    Expected type: IO
                     (Response Data.ByteString.Lazy.Internal.ByteString)
      Actual type: IO ()
    In the return type of a call of `putStrLn'
    In the expression: putStrLn "login failed"
    In the expression:
  if statusCode == 403 then putStrLn "login failed" else return ()

samplecode.hs:33:75:
    Couldn't match expected type `Response
                                    Data.ByteString.Lazy.Internal.ByteString'
                with actual type `()'
    In the first argument of `return', namely `()'
    In the expression: return ()
    In the expression:
      if statusCode == 403 then putStrLn "login failed" else return ()
Failed, modules loaded: none.

どうすれば修正できますか？

どうもありがとう

アップデート

Abrahamson のアドバイスに従って、コードを次のように少し変更し、StatusCodeException を適切に処理できるようになりました。

main = withSocketsDo $ do
    request' <- parseUrl "http://example.com/secret-page"
    let request = request' { cookieJar = Just $ createCookieJar [cookie] }
    eitherResp <- E.try (withManager $ httpLbs request)
    case eitherResp of
      Left (StatusCodeException s _ _) 
        | statusCode s == 403 -> putStrLn "login failed"
        | otherwise         -> return () 
      Right resp -> print (L.length (responseBody resp))